/* ----------------------------------------------------------------------    
* Copyright (C) 2010 ARM Limited. All rights reserved.    
*    
* $Date: 14/06/07 1:56a $Revision: 	V1.1.0  
*    
* Project: 	    CMSIS DSP Library    
* Title:		arm_cmplx_conj_q15.c    
*    
* Description:	Q15 complex conjugate.    
*    
* Target Processor: Cortex-M4/Cortex-M3/Cortex-M0
*  
* Version 1.1.0 2012/02/15 
*    Updated with more optimizations, bug fixes and minor API changes.  
*   
* Version 1.0.10 2011/7/15  
*    Big Endian support added and Merged M0 and M3/M4 Source code.   
*    
* Version 1.0.3 2010/11/29   
*    Re-organized the CMSIS folders and updated documentation.    
*     
* Version 1.0.2 2010/11/11    
*    Documentation updated.     
*    
* Version 1.0.1 2010/10/05     
*    Production release and review comments incorporated.    
*    
* Version 1.0.0 2010/09/20     
*    Production release and review comments incorporated.    
* ---------------------------------------------------------------------------- */

#include "arm_math.h"

/**    
 * @ingroup groupCmplxMath    
 */

/**    
 * @addtogroup cmplx_conj    
 * @{    
 */

/**    
 * @brief  Q15 complex conjugate.    
 * @param  *pSrc points to the input vector    
 * @param  *pDst points to the output vector    
 * @param  numSamples number of complex samples in each vector    
 * @return none.    
 *    
 * <b>Scaling and Overflow Behavior:</b>    
 * \par    
 * The function uses saturating arithmetic.    
 * The Q15 value -1 (0x8000) will be saturated to the maximum allowable positive value 0x7FFF.    
 */

void arm_cmplx_conj_q15(
  q15_t * pSrc,
  q15_t * pDst,
  uint32_t numSamples)
{

#ifndef ARM_MATH_CM0

  /* Run the below code for Cortex-M4 and Cortex-M3 */
  uint32_t blkCnt;                               /* loop counter */
  q31_t in1, in2, in3, in4;
  q31_t zero = 0;

  /*loop Unrolling */
  blkCnt = numSamples >> 2u;

  /* First part of the processing with loop unrolling.  Compute 4 outputs at a time.    
   ** a second loop below computes the remaining 1 to 3 samples. */
  while(blkCnt > 0u)
  {
    /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
    /* Calculate Complex Conjugate and then store the results in the destination buffer. */
    in1 = *__SIMD32(pSrc)++;
    in2 = *__SIMD32(pSrc)++;
    in3 = *__SIMD32(pSrc)++;
    in4 = *__SIMD32(pSrc)++;

#ifndef ARM_MATH_BIG_ENDIAN

    in1 = __QASX(zero, in1);
    in2 = __QASX(zero, in2);
    in3 = __QASX(zero, in3);
    in4 = __QASX(zero, in4);

#else

    in1 = __QSAX(zero, in1);
    in2 = __QSAX(zero, in2);
    in3 = __QSAX(zero, in3);
    in4 = __QSAX(zero, in4);

#endif //       #ifndef ARM_MATH_BIG_ENDIAN

    in1 = ((uint32_t) in1 >> 16) | ((uint32_t) in1 << 16);
    in2 = ((uint32_t) in2 >> 16) | ((uint32_t) in2 << 16);
    in3 = ((uint32_t) in3 >> 16) | ((uint32_t) in3 << 16);
    in4 = ((uint32_t) in4 >> 16) | ((uint32_t) in4 << 16);

    *__SIMD32(pDst)++ = in1;
    *__SIMD32(pDst)++ = in2;
    *__SIMD32(pDst)++ = in3;
    *__SIMD32(pDst)++ = in4;

    /* Decrement the loop counter */
    blkCnt--;
  }

  /* If the numSamples is not a multiple of 4, compute any remaining output samples here.    
   ** No loop unrolling is used. */
  blkCnt = numSamples % 0x4u;

  while(blkCnt > 0u)
  {
    /* C[0]+jC[1] = A[0]+ j (-1) A[1] */
    /* Calculate Complex Conjugate and then store the results in the destination buffer. */
    *pDst++ = *pSrc++;
    *pDst++ = __SSAT(-*pSrc++, 16);

    /* Decrement the loop counter */
    blkCnt--;
  }

#else

  q15_t in;

  /* Run the below code for Cortex-M0 */

  while(numSamples > 0u)
  {
    /* realOut + j (imagOut) = realIn+ j (-1) imagIn */
    /* Calculate Complex Conjugate and then store the results in the destination buffer. */
    *pDst++ = *pSrc++;
    in = *pSrc++;
    *pDst++ = (in == (q15_t) 0x8000) ? 0x7fff : -in;

    /* Decrement the loop counter */
    numSamples--;
  }

#endif /* #ifndef ARM_MATH_CM0 */

}

/**    
 * @} end of cmplx_conj group    
 */
